Troitsk is a town in Chelyabinsk Oblast, Russia, located 175 kilometers (109 mi) east of the southern Ural Mountains and approximately 110 kilometers (68 mi) south of Chelyabinsk on the border with Kazakhstan. It stands on the east-flowing Uy River, a branch of the Tobol River. Population: 78,372 (2010 Russian census); 83,862 ; 90,077 (1989 Soviet census).

Chelyabinsk Oblast is a federal subject of Russia in the Ural Mountains region, on the border of Europe and Asia. Its administrative center is the city of Chelyabinsk.